This study (ACTG 242) was a multicenter trial sponsored by the National Institute of Allergy and Infectious Diseases and was designed to determine the safety and efficacy of amitriptyline versus mexiletine in the treatment of painful peripheral neuropathy in AIDS. The two primary endpoints were 1) change of mean pain intensity score between baseline and eight weeks of treatment; and 2) assessment of drug-related toxicity. Patients (240 anticipated from all participating centers) were randomized in a double-blinded manner to one of three treatment arms: placebo, amitriptyline, or mexiletine and treated for ten weeks. Response to treatment was assessed by neurological examination and patient responses to standardized self-assessment pain questionnaires. However, interim analysis (137 patients) conducted during enrollment of our ACTG site (University of Pennsylvania) indicated no benefit above that seen in placebo-treated patients and the study was terminated on 1/3/97.